Unveiling potent bioactive compounds and anti-angiogenic pathways in Gekko swinhonis Guenther for gastric cancer therapy.

[ETHNOPHARMACOLOGICAL RELEVANCE] Gekko swinhonis Guenther, commonly referred to as Gecko in the following text, belongs to the genus Gekko within the family Gekko. Its dried whole body is a widely utilized traditional Chinese medicine, demonstrating significant efficacy in the treatment of gastrointestinal malignancies, particularly gastric cancer (GC). Nevertheless, the composition of the gecko is complex, necessitating further research into its active ingredients for the treatment of GC.

[AIM OF THE STUDY] Isolation and characterization of the most active components in Gecko based on their anti-GC mechanisms of vascular endothelial cell inhibition and anti-neovascularization.

[MATERIALS AND METHODS] We utilized the enzymatic hydrolysate of Geckos to investigate its effectiveness and underlying mechanisms. Initially, we assessed its efficacy in ectopic and in-situ GC tumor-bearing mouse models. Subsequently, we evaluated the effectiveness of peptides, aliphatics, and small molecules derived from Gecko using CCK-8 and 3D tumor spheroid assays. The activities of peptides S1-S4 were further examined through these experiments. Finally, we screened, synthesized, and investigated five potential peptides for their pharmacodynamics in the CCK-8 assay and in the in-situ GC model mice.

[RESULTS] The Gecko can inhibit the formation of blood vessels in the tumor microenvironment, providing a localized treatment for GC. The peptide components significantly inhibit vascular endothelial cells and impede the formation of new blood vessels, with the S2 peptide sections (0.3 KD - 3 KD) demonstrating the most potent inhibitory activity against angiogenesis. One of the active peptides effectively suppresses the growth of in-situ GC in nude mice through angiogenesis inhibition and also modulates immunity, all while exhibiting excellent biosafety.

[CONCLUSIONS] We have achieved a significant breakthrough in the local treatment of GC using Gecko. Through pharmacodynamic experiments and a systematic process of isolation and identification, we identified the most effective anti-GC ingredients of Gecko, based on their mechanisms of inhibiting vascular endothelial cells and promoting anti-angiogenesis. Furthermore, we synthesized a lead peptide that demonstrates promising therapeutic efficacy and safety.